The present invention relates to fertilizers for providing nutrients to plants, and in particular applies to an organic fertilizer that may be sprayed upon plants or plant soils as a liquid suspension.
It is well known in application of nutrient fertilizers to commercial crops such as vegetables and turfgrass that provision of macro nutrients nitrogen, phosphorus and potassium, and especially nitrogen is essential to achieving desired growth of the crops. For example, nitrogen fertilizers are typically applied to plant communities or to soils that are to support plant communities as inorganic nitrogen salts or as highly soluble urea. Upon exposure to soil moisture, irrigation or rain water, these salts become available for uptake into the target plants to provide the foundation for metabolism of proteins, etc., as is well known. Occasionally, nitrogen salts or urea granules are first dissolved in water and applied directly to the plants or soils as a solute through a liquid applicator such as a spray machine or an irrigation system.
There are many benefits to application of such highly soluble nitrogen compounds directly to plant communities. The application can be carefully metered to achieve a desired cultural practice, such as promoting a quick flush of growth of a turfgrass after a winter dormancy to encourage dominance of the desired turfgrass over undesired, and still dormant or annual weeds in order to minimize usage of any herbicides to control weed growth. High frequency, low concentration applications can be meticulously applied to achieve optimum growth, and a winter hardening off can be assisted by precise control of fertility in the pre-winter months. Additionally, in highly sensitive greenhouse production, or in drip irrigation in arid orchard crop production, a precise amount of liquid nitrogen solutes may be delivered to target plants without wasting valuable nutrients in fertilizing non-target, adjacent plant communities.
It is increasingly recognized, however, that application of inorganic, highly soluble fertilizers, and especially fertilizers that provide nitrogen, has many deleterious effects, especially on the ecosystem of the plant communities targeted for application of the fertilizers, and for adjacent and even far removed ecosystems. Perhaps the most recognized drawback of soluble inorganic fertilizers is leaching of the nutrients into ground water. Whenever water infiltration through a soil exceeds the combination of evaporation of ground water from the soil and transpiration of ground water through a plant community, the excess water moves or leaches below the plant root zone into subterranean water movement to ultimately flow into nearby streams, aquifers, ponds, lakes, rivers, and ultimately the oceans of the world. Solutes such as nitrate and ammonium freely move with the leachate solution to increase ordinary nitrogen content of the streams, ponds, lakes, etc., which dramatically alters their ecosystems. One well-known effect frequently referred to as eutrophication is to enhance plant growth in the streams, ponds and lakes so that the ordinary dissolved oxygen content of the water is diminished, thereby decreasing available oxygen for fish that may eat the plants so that formerly pristine recreational bodies of water become weed infested, unsightly, unpleasant, and unusable problems for communities. Even more troublesome than such increased nitrogen content of streams, ponds or lakes, etc., is a concern for such nitrogen solutes in aquifers and human drinking water such as in deep wells, etc. While careful application of inorganic fertilizers may ameliorate some of this well documented problem, the unpredictability of weather conditions always poses a risk of leaching major proportions of soluble, inorganic fertilizer applications into moving ground water, such as by a sudden downpour of an inch or more of water immediately after application of such fertilizers; a very common problem in fine turfgrass culture, such as on golf courses, parks, athletic fields, etc.
Golf course fine quality turfgrasses pose a special risk of loss of soluble inorganic fertilizers. That is because it is increasingly common to utilize sand having an optimal particle size range as a major or total constituent of the root zone soil to minimize problems related to compaction due to repeated high traffic over limited turfgrass areas. While increasing sand as a constituent of the soil, or using total sand soils of specific particle size ranges, helps turfgrasses withstand high traffic, such sand soils are especially susceptible to leaching of soluble nutrients into ground water that moves the nitrogen solutes away from the target turfgrass plants and into aquifers, streams, etc.
Many efforts have been undertaken to develop slow release nitrogen fertilizers through complicated encapsulation and/or granulation methods that rely upon compounds such as urea. While some such expensive fertilizers have received limited acceptance, the vast majority of nitrogen fertilizers world-wide still include highly soluble, inorganic nitrogen salts or urea that produce nitrate or ammonium ions that freely leach from soils of target plant communities, and that are wasteful as fertilizer and disruptive of the larger ecosystem.
Additional efforts have focused upon using organic fertilizers from plant and animal sources that provide nitrogen in a slowly released form to avoid leaching of the fertilizer into ground water. To date, however, organic fertilizers have met with only limited acceptance due to substantial difficulties. One such difficulty is a low amount of nitrogen that is only slowly available. An example of an organic fertilizer that has had some success is sold under the trademark xe2x80x9cMILORGANITExe2x80x9d, that is made by the Milwaukee Metropolitan Sewerage District company, of Milwaukee, Wis., U.S.A. xe2x80x9cMILORGANITExe2x80x9d has a macro nutrient, or nitrogen, phosphorous, potassium, weight percent analysis of 6.75% nitrogen, 2.65% phosphorus, and 0.46% potassium and approximately 83% of the nitrogen is water insoluble. xe2x80x9cMILORGANITExe2x80x9d organic fertilizer is frequently used in professional turfgrass culture and non-food horticulture such as perennial and annual flower production. However, it is virtually never the sole fertilizer for managers of such crops, and typically must be utilized with traditional highly soluble inorganic salt or urea types of nitrogen fertilizers. More traditional organic fertilizers, such as raw or processed animal waste products have problems related to low and slowly available nitrogen release rates, and also have severe use limitations based upon unacceptable odors, and application restrictions to live plant communities, such as turfgrass plantings in athletic fields, home lawns, cemeteries, parks, golf courses, etc. and have some limited utility in tilled soils prior to seeding.
Accordingly, there is a need for an organic fertilizer that will provide a substantial amount of nitrogen to target plant communities at a rate commensurate with plant nutritional needs and desired cultural practices, that will enhance the ecosystem of the soil within which the plant is growing, and that will not be leached from the soil.
The invention is a sprayable organic fertilizer for application to a plant or plant soil that includes denatured soybean particles having a total protein content of at least fifty (50) percent by weight, wherein the denatured soybean particles have a particle size of no greater than 250 microns, and wherein the denatured soybean particles are dispersed in an adequate amount of a liquid carrier so that the particles may be evenly sprayed onto the plant or plant soil through a liquid applicator. In a preferred embodiment, the denatured soybean particles are mixed with a yeast extract that stimulates microbial growth. The yeast extract may be between 0.1 percent and 1.0 percent by weight of the sprayable organic fertilizer. In an additional preferred embodiment, the denatured soybean particles have a total protein content of at least ninety (90) percent by weight, and the liquid carrier in which the particles are dispersed is an agitated liquid.
By the phrase xe2x80x9cdenatured soy bean particlesxe2x80x9d, it is meant that a soy bean meal is first treated to have vegetable oil extracted, and the remaining soy bean meal is then treated to have water soluble compounds removed leaving a denatured soy bean, which is then ground to produce denatured soy bean particles having a particle size of no greater than 250 microns.
It is stressed that it is well known in efforts to produce fertilizer compounds that soy bean derived products are commonly used. However, until the development by the inventors herein of the sprayable organic fertilizer described above using a form of denatured soy bean particles, it was only known to use xe2x80x9chydrolyzedxe2x80x9d, xe2x80x9csolublizedxe2x80x9d, or xe2x80x9cactivatedxe2x80x9d soy bean proteins as a direct fertilizer source. It was generally considered that denatured soy bean particles, or denatured soy bean isolates were not soluble in polar solvents such as water. For example, in U.S. Pat. No. 4,370,159 that issued on Jan. 25, 1983 to Holtz, a conglomerate particle is disclosed that utilizes denatured soy protein as a xe2x80x9cmatrixxe2x80x9d (see Col. 3, lines 52-68) to support enhancer droplets within folds of the denatured protein matrix, wherein the enhancer droplets are held within the folds of the matrix by formyl bridges, and the enhancer droplets include activated soy protein with activator materials, water and vegetable oils to make the activated material an available nutrient. Other U.S. Patents and agricultural documents consistently recite that denatured soy bean particles (frequently referred to as xe2x80x9csoy protein isolatesxe2x80x9d) are too insoluble for application as a fertilizer source of nitrogen directly to plants or plant soils. (For example, see U.S. Pat. No. 4,818,268, that issued on Apr. 4, 1989 also to Holtz, at Col. 5, lines 37-46.)
The inventors of the present sprayable organic fertilizer including denatured soy particles came upon the realization of the value of denatured soy protein particles through usage of such particles as components of a microbial growth medium for laboratory growth and study of various microorganisms. Recognizing the success of the denatured soy particles in laboratory growth of the microorganisms, the inventors concluded field growth of microorganisms may also be substantially assisted by application of the same denatured soy particles to plant communities. After considerable research of resulting increases in microbial growth in field studies, the inventors have concluded that the enhanced microflora have also effectively broken down the denatured soy protein particles into plant available nutrients, so that an unexpected direct fertility effect has been achieved. In particular, the embodiment of the sprayable organic fertilizer that includes a total protein content of at least 50 percent provides at least 8.5 percent nitrogen by weight, and the embodiment that includes a total protein content of at least 90 percent provides at least 14.5 percent nitrogen by weight.
It is the further conclusion of the inventors that their sprayable organic fertilizer is not only insoluble and hence immune from leaching out of the root zone, but that the denatured soy protein particles must first be metabolized by the microflora to produce plant available nitrate and ammonium ions. Therefore the inventors""sprayable organic fertilizer necessarily enhances a healthy, stable ecosystem within the root zone of the target plants. That is because the microflora first reach and maintain a stable growth and decomposition rate, and the nutrients in the denatured soy protein particles become plant available ions for the target plants only after the particles are first ingested as needed and broken down by the microbes to become plant available ions.
It is theorized that prior fertilizer development efforts failed to appreciate the value of denatured soy protein particles because such efforts focused upon a direct effect of potential nutrient formulations upon target plant communities, as opposed to focusing upon an indirect effect that also involves a nutrient effect upon the entire ecosystem of a target plant, and in particular the microflora of a root zone. By enhancing and stabilizing the ecosystem of the root zone, the present sprayable organic fertilizer including denatured soy protein particles not only provides a slow release, non-leaching, high nitrogen source, but also creates a substantially healthier overall ecosystem in which the target plant grows, thereby diminishing a survival capacity of invasive pathogens that could attack the target plants.
Because the denatured soy protein particles are not soluble, they cannot be suddenly leached away due to excess water. Moreover, they cannot xe2x80x9cburnxe2x80x9d target plants in the event of an over application of the sprayable organic fertilizer because the insoluble denatured soy protein particles cannot effect a high-solubility induced reverse-osmosis killing of target plants, which is a common and well known problem associated with soluble inorganic fertilizers.
The characterization of the denatured soy particles as having a particle size xe2x80x9cno greater than 250 micronsxe2x80x9d refers to a diameter of the particles, and is intended to be a maximum size that will support even distribution of the particles as suspended in a liquid carrier, such as water. It is stressed that the water carrier does not render the denatured soy bean protein particles soluble, but instead is necessary for an even spray or distribution by a liquid applicator of the particles onto a target plant community or plant soil. By stating the xe2x80x9cdenatured soybean particles are dispersed in an adequate amount of a liquid carrier so that the particles may be evenly sprayedxe2x80x9d or distributed onto the plant or plant soil, it is meant that the dispersion into the liquid carrier is sufficiently dilute that the resulting spray or distribution onto the plant or plant soil effects a uniform growth of the target plant, or plant community, as opposed to a spotty, xe2x80x9cpolka-dotishxe2x80x9d, or inconsistent growth of the plants.
The liquid applicator may be a standard pressurized tank with one or more spray nozzle outlets, or an irrigation system that injects fertilizer (xe2x80x9cfertigationxe2x80x9d) into pipes to be dispensed with irrigation water through standard irrigation heads. Because of the particle size of the denatured soy particles, it may be necessary to utilize an agitator, such as a rotating arm within a tank, especially for a static fertigation tank, unlike a tractor pulled or hand carried pressure tank, to maintain an even dispersion of the particles in the liquid carrier, and to avoid clogging of spray nozzles of the liquid applicator.
Accordingly, it is a general object of the present invention to provide a sprayable organic fertilizer that overcomes deficiencies of prior art fertilizers.
It is a more specific object to provide a sprayable organic fertilizer that enhances an ecosystem of the target plant community or plant soil to which the fertilizer is applied while supplying a high rate of nitrogen.
It is yet another object to provide a sprayable organic fertilizer that becomes available as a nutrient for a target plant based upon nutrient needs of the ecosystem of the plant community.
It is a further object to provide a sprayable organic fertilizer that cannot be leached from plant soils and that cannot burn target plants.
These and other objects and advantages of this invention will become more readily apparent when the following description is read in conjunction with the accompanying drawings.